Adsorption mechanism of yttrium ions onto ion-adsorption type rare earths ore

• Ion-adsorption type rare earths desorption residues as adsorbents. • The maximum Y(III) adsorption capacity of 4.45 mg·g -1 . • Y(III) adsorbed onto the adsorbents surface possibly via Si-O-Y bond. • Adsorption process governed by chemical adsorption. Ion-adsorption type rare earths ore, as the primary source for middle-heavy rare earth elements, was extracted by various electrolytes via the adsorption-desorption effect. In this work, adsorption behavior and mechanism for yttrium ions onto ion-adsorption type rare earths ore as adsorbents were investigated systematically and comprehensively. The isotherms and kinetics suggested the adsorption of yttrium ions was consistent to Langmuir and pseudo-second-order model, revealing that the adsorption process was homogeneous and primarily governed by chemical adsorption. Maximum adsorption capacity could attain as 4.45 mg·g −1 in pH of 3 with 10 g·L −1 yttrium ions. Moreover, thermodynamics analysis indicated the adsorption process was spontaneous, and random. ATR-FTIR, XPS and DFT results indicated that Y(III) adsorbed onto ion-adsorption type rare earths ore surface possibly via Si-O-Y bond.